Calibrating a vibrational output device

Abstract

Examples are disclosed herein that relate to avoiding mechanical noise from operation of a vibrational output device. One example provides a computing device including a processor and a storage device storing instructions executable by the processor to vary a drive voltage applied to a vibrational output device, receive acoustic data, and from the acoustic data detect a noise signal from the vibrational output device as the drive voltage is varied. The instructions are further executable to, based upon the detected noise signal, select an operational drive voltage for the vibrational output device, and operate the vibrational output device using the operational drive voltage.

The invention claimed is: 
     
       1. A computing device comprising:
 a processor; and 
 a storage device storing instructions executable by the processor to, during manufacturing of a mobile device,
 vary a drive voltage applied to a vibrational output device of the mobile device by sweeping the drive voltage through a range of voltages, 
 receive acoustic data, 
 from the acoustic data, detect a noise signal arising from contact between the vibrational output device and another internal part of the mobile device as the drive voltage is swept through the range of voltages, 
 calibrate the vibrational output device by, based upon the detected noise signal, selecting an operational drive voltage for the vibrational output device, and 
 operate the vibrational output device using the operational drive voltage. 
 
 
     
     
       2. The computing device of  claim 1 , wherein the instructions are executable to detect a noise signal by applying a bandpass filter configured to pass a mechanical noise frequency of the vibrational output device. 
     
     
       3. The computing device of  claim 1 , wherein the instructions are executable to receive acoustic data from one or more microphones internal to the computing device. 
     
     
       4. The computing device of  claim 1 , wherein the instructions are further executable to compare a detected magnitude of the noise signal to a threshold magnitude, and select the operational drive voltage such that the detected magnitude of the noise signal is below the threshold magnitude. 
     
     
       5. The computing device of  claim 1 , wherein the instructions are executable to calibrate the vibrational output device during manufacturing. 
     
     
       6. The computing device of  claim 1 , wherein the instructions are further executable to transform the acoustic data from a time domain to a frequency domain. 
     
     
       7. The computing device of  claim 1 , wherein the instructions are further executable to obtain a background noise level, and not perform a calibration of the vibrational output device based on the background noise level exceeding a threshold background noise level. 
     
     
       8. The computing device of  claim 1 , wherein the computing device is the mobile device. 
     
     
       9. The computing device of  claim 8 , wherein the mobile device comprises one or more of a phone, a tablet, a laptop, a mouse, and a game controller. 
     
     
       10. A computing device comprising:
 a vibrational output device; 
 a microphone; 
 a processor; and 
 storage comprising instructions executable by the processor to
 vary a drive voltage applied to the vibrational output device by sweeping the drive voltage through a range of voltages, 
 receive acoustic data via the microphone, 
 from the acoustic data, detect a noise signal arising from contact between the vibrational output device and another internal part of the computing device as the drive voltage is swept through the range of voltages, 
 calibrate the vibrational output device by, based upon the detected noise signal, selecting an operational drive voltage for the vibrational output device, and 
 operate the vibrational output device using the operational drive voltage. 
 
 
     
     
       11. The computing device of  claim 10 , wherein the instructions executable to detect a noise signal comprises instructions executable to apply a bandpass filter to pass a mechanical noise frequency of the vibrational output device. 
     
     
       12. The computing device of  claim 10 , wherein the instructions are further executable to compare a detected magnitude of the noise signal to a threshold magnitude, and select the operational drive voltage such that the detected magnitude is below the threshold magnitude. 
     
     
       13. The computing device of  claim 10 , wherein the instructions are executable to calibrate the vibrational output device during manufacturing. 
     
     
       14. The computing device of  claim 10 , wherein the instructions are executable to calibrate the vibrational output device during ordinary use. 
     
     
       15. The computing device of  claim 14 , wherein the instructions are executable to calibrate the vibrational output device based on user input. 
     
     
       16. The computing device of  claim 10 , wherein the instructions are further executable to obtain a background noise level, and not perform calibration based on the background noise level exceeding a threshold background noise level. 
     
     
       17. The computing device of  claim 10 , wherein the instructions are further executable to attenuate noise arising from an external surface contacting the computing device due to vibration of the vibrational output device. 
     
     
       18. On a computing device, a method of selecting a drive voltage for operating a vibrational output device of a mobile device, the method comprising:
 obtaining a background noise level; 
 when the background noise level does not exceed a threshold background noise level, then performing a calibration of the vibrational output device by
 during operation of the vibrational output device, varying a drive voltage of the vibrational output device of the mobile device and receiving acoustic data from one or more microphones of the computing device, 
 from the acoustic data, detecting a noise signal arising from contact between the vibrational output device and another internal part of the mobile device as the drive voltage is varied, and 
 calibrating the vibrational output device by, based upon the detected noise signal, selecting an operational drive voltage for the vibrational output device; and 
 
 when the background noise level does exceed the threshold background noise level, then not performing the calibration of the vibrational output device. 
 
     
     
       19. The method of  claim 18 , wherein detecting operation of the vibrational output device comprises detecting an event for which the computing device provides vibrational output. 
     
     
       20. The method of  claim 18 , further comprising obtaining the background noise level at a time when acoustic output and vibrational output are in an off state.